/* ===== Reset & Variables ===== */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --bg: #0a0a0f;
  --bg-alt: #101018;
  --surface: #16161f;
  --surface-hover: #1e1e2a;
  --border: #2a2a3a;
  --text: #e8e8ef;
  --text-secondary: #9898a8;
  --accent: #6c8aff;
  --accent-hover: #8ba3ff;
  --accent-glow: rgba(108, 138, 255, 0.15);
  --gradient-1: #6c8aff;
  --gradient-2: #a78bfa;
  --gradient-3: #38bdf8;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
  --transition: 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="light"] {
  --bg: #fafafa;
  --bg-alt: #f0f0f5;
  --surface: #ffffff;
  --surface-hover: #f5f5fa;
  --border: #e0e0ea;
  --text: #1a1a2e;
  --text-secondary: #6a6a7a;
  --accent: #4a6adf;
  --accent-hover: #3a5ad0;
  --accent-glow: rgba(74, 106, 223, 0.1);
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
}

body {
  font-family: var(--font-body);
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  overflow-x: hidden;
  transition: background var(--transition), color var(--transition);
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: color var(--transition);
}

a:hover {
  color: var(--accent-hover);
}

/* ===== Background Canvas ===== */
#bg-canvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
  pointer-events: none;
  opacity: 0.4;
}

[data-theme="light"] #bg-canvas {
  opacity: 0.6;
}

/* ===== Navbar ===== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 clamp(1.5rem, 5vw, 4rem);
  height: 70px;
  background: transparent;
  transition: background var(--transition), box-shadow var(--transition),
              backdrop-filter var(--transition);
}

.navbar.scrolled {
  background: color-mix(in srgb, var(--bg) 80%, transparent);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  box-shadow: 0 1px 0 var(--border);
}

.nav-logo {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--text);
  letter-spacing: -0.02em;
}

.nav-links {
  display: flex;
  gap: 2rem;
}

.nav-links a {
  color: var(--text-secondary);
  font-size: 0.875rem;
  font-weight: 500;
  letter-spacing: 0.01em;
  position: relative;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--accent);
  transition: width var(--transition);
}

.nav-links a:hover {
  color: var(--text);
}

.nav-links a:hover::after {
  width: 100%;
}

.theme-toggle {
  background: none;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 8px;
  cursor: pointer;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition);
}

.theme-toggle:hover {
  color: var(--text);
  border-color: var(--text-secondary);
}

.icon-moon {
  display: block;
}

.icon-sun {
  display: none;
}

[data-theme="light"] .icon-moon {
  display: none;
}

[data-theme="light"] .icon-sun {
  display: block;
}

/* ===== Hero ===== */
.hero {
  position: relative;
  z-index: 1;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 100px clamp(1.5rem, 5vw, 4rem) 60px;
}

.hero-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
  max-width: 1200px;
  margin: 0 auto;
  width: 100%;
}

.hero-greeting {
  font-family: var(--font-mono);
  font-size: 0.95rem;
  color: var(--accent);
  margin-bottom: 0.75rem;
}

.hero-name {
  font-size: clamp(2.5rem, 6vw, 4.5rem);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.03em;
  margin-bottom: 1rem;
  background: linear-gradient(135deg, var(--gradient-1), var(--gradient-2), var(--gradient-3));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-tagline {
  font-size: clamp(1.1rem, 2vw, 1.35rem);
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
  font-weight: 500;
}

.hero-description {
  color: var(--text-secondary);
  max-width: 500px;
  margin-bottom: 2rem;
  font-size: 1rem;
}

.hero-cta {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  padding: 0.75rem 1.75rem;
  border-radius: 10px;
  font-weight: 600;
  font-size: 0.9rem;
  transition: all var(--transition);
  cursor: pointer;
}

.btn-primary {
  background: var(--accent);
  color: #fff;
}

.btn-primary:hover {
  background: var(--accent-hover);
  color: #fff;
  transform: translateY(-1px);
  box-shadow: 0 8px 24px var(--accent-glow);
}

.btn-outline {
  border: 1px solid var(--border);
  color: var(--text);
  background: transparent;
}

.btn-outline:hover {
  border-color: var(--accent);
  color: var(--accent);
  transform: translateY(-1px);
}

.hero-visual {
  display: flex;
  align-items: center;
  justify-content: center;
}

.point-cloud {
  width: 100%;
  max-width: 450px;
  aspect-ratio: 1;
  position: relative;
}

.scroll-indicator {
  position: absolute;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
  color: var(--text-secondary);
  font-size: 0.75rem;
  font-family: var(--font-mono);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  opacity: 0.6;
}

.scroll-line {
  width: 1px;
  height: 40px;
  background: linear-gradient(to bottom, var(--accent), transparent);
  animation: scroll-pulse 2s ease-in-out infinite;
}

@keyframes scroll-pulse {
  0%, 100% { opacity: 0.3; transform: scaleY(0.6); }
  50% { opacity: 1; transform: scaleY(1); }
}

/* ===== Sections ===== */
.section {
  position: relative;
  z-index: 1;
  padding: 6rem 0;
}

.section-alt {
  background: var(--bg-alt);
}

.section-container {
  max-width: 1000px;
  margin: 0 auto;
  padding: 0 clamp(1.5rem, 5vw, 4rem);
}

.section-title {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 3rem;
  letter-spacing: -0.02em;
  position: relative;
  display: inline-block;
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: -8px;
  left: 0;
  width: 40px;
  height: 3px;
  background: linear-gradient(90deg, var(--gradient-1), var(--gradient-2));
  border-radius: 2px;
}

/* ===== About ===== */
.about-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr;
  gap: 3rem;
  align-items: start;
}

.about-text p {
  color: var(--text-secondary);
  margin-bottom: 1rem;
}

.about-text strong {
  color: var(--text);
}

.about-interests h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 1rem;
  color: var(--text);
}

.tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.tag {
  display: inline-block;
  padding: 0.35rem 0.85rem;
  background: var(--accent-glow);
  border: 1px solid color-mix(in srgb, var(--accent) 30%, transparent);
  border-radius: 20px;
  font-size: 0.8rem;
  color: var(--accent);
  font-weight: 500;
  transition: all var(--transition);
}

.tag:hover {
  background: color-mix(in srgb, var(--accent) 20%, transparent);
  transform: translateY(-1px);
}

/* ===== Publications ===== */
.publications-list {
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

.pub-card {
  position: relative;
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: 1.5rem;
  padding: 1.5rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 14px;
  transition: all var(--transition);
}

.pub-card:hover {
  border-color: color-mix(in srgb, var(--accent) 40%, transparent);
  box-shadow: 0 4px 24px var(--accent-glow);
  transform: translateY(-2px);
}

.pub-thumbnail {
  border-radius: 10px;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
}

.pub-thumbnail img {
  width: 100%;
  height: auto;
  display: block;
  cursor: pointer;
  transition: all 0.5s ease;
}

.pub-thumbnail:hover img {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: contain;
  background: var(--surface);
  z-index: 10;
  border-radius: 14px;
  padding: 1rem;
}

.pub-placeholder {
  color: var(--text-secondary);
  opacity: 0.4;
}

.pub-title {
  font-size: 1.15rem;
  font-weight: 600;
  margin-bottom: 0.4rem;
  line-height: 1.3;
}

.pub-authors {
  font-size: 0.875rem;
  color: var(--text-secondary);
  margin-bottom: 0.25rem;
}

.pub-venue {
  font-size: 0.85rem;
  color: var(--accent);
  font-family: var(--font-mono);
  margin-bottom: 0.75rem;
}

.pub-abstract {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 0.75rem;
}

.pub-links {
  display: flex;
  gap: 0.75rem;
}

.pub-link {
  display: inline-flex;
  align-items: center;
  padding: 0.3rem 0.8rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: all var(--transition);
}

.pub-link:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--accent-glow);
}

/* ===== Projects ===== */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.5rem;
}

.project-card {
  padding: 1.5rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 14px;
  transition: all var(--transition);
  display: flex;
  flex-direction: column;
}

.project-card:hover {
  border-color: color-mix(in srgb, var(--accent) 40%, transparent);
  box-shadow: 0 4px 24px var(--accent-glow);
  transform: translateY(-3px);
}

.project-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.25rem;
  color: var(--accent);
}

.project-links-top a {
  color: var(--text-secondary);
  transition: color var(--transition);
}

.project-links-top a:hover {
  color: var(--text);
}

.project-title {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.project-desc {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.6;
  flex: 1;
  margin-bottom: 1.25rem;
}

.project-tech {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.project-tech span {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-secondary);
}

.project-tech span::before {
  content: '#';
  color: var(--accent);
  margin-right: 2px;
}

.projects-placeholder {
  text-align: center;
  color: var(--text-secondary);
  font-size: 1.1rem;
  padding: 3rem 0;
}

/* ===== Contact ===== */
.contact-content {
  text-align: center;
  max-width: 800px;
  margin: 0 auto;
}

.contact-content > p {
  color: var(--text-secondary);
  margin-bottom: 2rem;
}

.contact-links {
  display: flex;
  justify-content: center;
  gap: 1.5rem;
  flex-wrap: nowrap;
}

.contact-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
  padding: 1.25rem 1.5rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 14px;
  color: var(--text-secondary);
  font-size: 0.85rem;
  font-weight: 500;
  min-width: 100px;
  transition: all var(--transition);
}

.contact-item:hover {
  color: var(--accent);
  border-color: var(--accent);
  transform: translateY(-3px);
  box-shadow: 0 4px 24px var(--accent-glow);
}

/* ===== Footer ===== */
.footer {
  position: relative;
  z-index: 1;
  text-align: center;
  padding: 2rem;
  color: var(--text-secondary);
  font-size: 0.8rem;
  border-top: 1px solid var(--border);
}

/* ===== Animations ===== */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.9s ease, transform 0.9s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===== Responsive ===== */
@media (max-width: 900px) {
  .hero-content {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero-description {
    margin-left: auto;
    margin-right: auto;
  }

  .hero-cta {
    justify-content: center;
  }

  .hero-visual {
    display: none;
  }

  .about-grid {
    grid-template-columns: 1fr;
  }

  .pub-card {
    grid-template-columns: 1fr;
  }

  .pub-thumbnail {
    max-height: 160px;
  }
}

@media (max-width: 600px) {
  .nav-links {
    display: none;
  }

  .hero {
    min-height: 90vh;
  }

  .section {
    padding: 4rem 0;
  }

  .projects-grid {
    grid-template-columns: 1fr;
  }

  .contact-links {
    flex-wrap: wrap;
  }
}